The Center for Disease Control (CDC) estimates that hospital-acquired infections cost the U.S. healthcare system $4.5 billion a year, and that 80% of these infections are transmitted by direct touch. Although the simple use of soap before and after direct contact with a patient can reduce the transmission of these infections, health care workers often fail to employ this simple measure for several reasons. First, washing with soap and water takes time. Second, such washing necessitates the use of running water, sinks, paper towels and other infrastructural needs that are expensive to provide and maintain and therefore not always immediately accessible by health-care personnel. Thus, most health care workers follow the existing washing guidelines only about 50% of the time.
In response to this problem, the CDC recently issued new hand hygiene guidelines for health care workers. One recommendation is for doctors, nurses and other health care workers to use alcohol-based hand antiseptics rather than traditional water-based soaps to decontaminate their hands between contact with each patient to prevent the spread of infections. This new CDC guideline is expected to reduce the time spent to decontaminate hands and hence increase compliance among health-care workers. Moreover, the recommended alcohol-based products can be carried with the health care worker or installed in several convenient places near patient rooms. The alcohol in the lotion will kill the bacteria, and added emollients should keep the hands soft. Furthermore, the product dries on the hands, so running water, sinks, paper towels, etc. are largely unnecessary.
A product called Avagard™, made by 3M, is commercially available having a combination of emulsifiers, namely Beheneth-10, behenyl alcohol, cetylpalmitate, and diisopropyl dimer dilinoleate with 1% chlorhexidine gluconate solution and 61% ethyl alcohol (w/w).
A product called Prevacare D™, made by Johnson & Johnson, is commercially available having 60% ethanol as its active ingredient, water as a vehicle, liposome-building blocks including glycerol distearate, stearate-10, cholesterol, and polysorbate 80, sodium laureth sulfate as a surfactant, propylene glycol as a moisturizer, and preservatives including diazolidinyl urea, methylparaben, and propylparaben. Prevacare-D™ is a commercially available product having 60% ethanol as its active ingredient, and also includes cyclomethicone as an emollient, polyethylene and silica as viscosity builders, mineral oil as a moisturizer/emollient, propylparaben as a preservative and fragrance.
A principal drawback with the increased use of alcohol-based products such as Avagard™, Prevacare D™, or others presently available or embodied in various issued U.S. or European patents (see e.g. U.S. Pat. No. 3,485,915, U.S. Pat. No. 4,478,853, U.S. Pat. No. 4,956,170, U.S. Pat. No. 5,403,864, U.S. Pat. No. 5,516,510, U.S. Pat. No. 5,776,430, U.S. Pat. No. 5,885,562, U.S. Pat. No. 5,951,993, U.S. Pat. No. 6,022,551, U.S. Pat. No. 6,107,261, U.S. Pat. No. 6,136,771, U.S. Pat. No. 6,204,230, U.S. Pat. No. 6,352,701, and European Patent Application 0604 848) is that certain ingredients in the formulations, including the alcohol itself, may cause irritation and allergic reactions on the skin. This drawback was readily apparent in a recent study of alcohol-based disinfectants among nurses, which showed that adverse reactions occurred in approximately 12% of all individuals following exposure to these products (Cimiotti et al., 2003, Am. J. Infect. Control 31:43-48). The instant invention provides one means of overcoming this problem. Certain zinc salts may be added to alcohol-based gels, hand scrubs or other products to prevent the irritation that may otherwise be caused by the alcohol or other active or inactive ingredients that they may contain (see e.g. U.S. Pat. No. 5,965,610 and U.S. Pat. No. 5,985,918, the contents of which are incorporated by reference herein).
Transmission of infectious diseases is also a serious public health concern outside of the health care setting. For example, a growing number of infectious agents may be transmitted by sexual contact, and public health experts increasingly advocate the use of various devices or substances to reduce or prevent the transmission of infectious agents during sexual contact. Unfortunately, such devices or substances often contain irritating components or ingredients that may cause irritation or the dermis or mucous membranes, thereby actually increasing the risk of infection. For example, male or female condoms are often made from latex or other potentially irritating substances. Genital creams, lotions or ointments often contain potentially irritating microbicides, fungicides or spermicides.
In addition to or as an alternative to antimicrobial topical formulations, gloves are used by health care practioners and in other sectors, such as the food service industry, as a means of preventing spread of infection. However, many persons have or develop sensitivities to gloves, including allergic reactions to latex or dermatologic reactions to moisture retention.
Therefore, the primary means of preventing spread of infection are associated with skin irritation. There is a need to develop products that inhibit or prevent this irritation as a step toward making anti-infective formulations and articles more user-friendly and increasing compliance.
It has been recognized that zinc salts can inhibit irritation caused by a variety of agents. See for example, U.S. Pat. Nos. 5,708,023, 5,965,610, 6,037,386, and 5,985,918, These patents teach the use of relatively high concentrations of zinc, which might be detrimental if taken internally. Apart from the potential for systemic zinc toxicity following the absorption of high concentration water-soluble zinc salts through the skin or mucosa following their use in topical creams or gels, zinc itself may be an irritant at high concentrations. Thus, there is a practical upper limit to the amount of zinc in products designed for internal use. Further, as a result of the ability of zinc to bind to and subsequently inactivate potential irritants such as the contraceptive or antiseptic agent, the inclusion of high concentrations of zinc salts in these products may render them ineffective for their intended functions.
U.S. Pat. Nos. 5,980,477 and 6,321,750 of Kelly relate to the incorporation of water-soluble, organic salts of zinc as anti-viral agents into genital lubricants or other similar products. Kelly does not appreciate or describe the beneficial anti-irritant effects of low concentrations of combinations of water-soluble, organic salts of zinc.